Molecular dynamics simulation of the combination effect of the tip inclination and scratching direction on nanomachining of single crystal silicon

Three-dimensional molecular dynamics simulations have been performed to investigate the combination effect of the tip inclination and scratching direction on the tip-based nanomanufacturing (TBN) process of single crystal silicon. Three typical scratching directions, edge forward (EF), face forward (FF), and side-face forward (SFF), were considered in the TBN processes. By analyzing the variation of the projected area of the tip, groove morphology, and silicon atomic flow behavior, the simulation results showed that the tip inclination and scratching direction had significant influences on groove generation, which is caused by the various atomic flow directions for scratching with different inclination angles and scratching directions. The change of the contact area induced by the tip inclination and scratching direction was the main reason for the variation of the scratching forces, and the normal forces were more sensitive than the tangential forces. Moreover, the plastic behavior, including the hydrostatic stress distribution, phase transformation, and the amorphous silicon distribution, were also dependent on the combination effect of the tip inclination and scratching direction. The results will provide important guidance for the process of TBN on silicon materials.